[patch 35/38] s390: Select ARCH_HAS_RANDOM_ENTROPY

Thomas Gleixner
2026-04-10T12:21:49Z

The only remaining non-architecture usage of get_cycles() is to provide
random_get_entropy().

Switch s390 over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY and
providing random_get_entropy() in asm/random.h.

Add 'asm/timex.h' includes to the relevant files, so the global include can
be removed once all architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
---
arch/s390/Kconfig | 1 +
arch/s390/include/asm/random.h | 12 ++++++++++++
arch/s390/include/asm/timex.h | 6 ------
arch/s390/kernel/time.c | 1 +
arch/s390/kernel/vtime.c | 1 +
5 files changed, 15 insertions(+), 6 deletions(-)

--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -108,6 +108,7 @@ config S390
select ARCH_HAS_PREEMPT_LAZY
select ARCH_HAS_PTDUMP
select ARCH_HAS_PTE_SPECIAL
+ select ARCH_HAS_RANDOM_ENTROPY
select ARCH_HAS_SCALED_CPUTIME
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_SET_MEMORY
--- /dev/null
+++ b/arch/s390/include/asm/random.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_RANDOM_H
+#define _ASM_S390_RANDOM_H
+
+#include <asm/timex.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+ return (unsigned long)get_tod_clock_monotonic() >> 2;
+}
+
+#endif
--- a/arch/s390/include/asm/timex.h
+++ b/arch/s390/include/asm/timex.h
@@ -219,12 +219,6 @@ static inline unsigned long get_tod_cloc
return tod;
}

-static inline cycles_t get_cycles(void)
-{
- return (cycles_t)get_tod_clock_monotonic() >> 2;
-}
-#define get_cycles get_cycles
-
/**
* tod_to_ns - convert a TOD format value to nanoseconds
* @todval: to be converted TOD format value
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -50,6 +50,7 @@
#include <asm/irq_regs.h>
#include <asm/vtimer.h>
#include <asm/stp.h>
+#include <asm/timex.h>
#include <asm/cio.h>
#include "entry.h"

--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -14,6 +14,7 @@
#include <linux/time.h>
#include <asm/alternative.h>
#include <asm/cputime.h>
+#include <asm/timex.h>
#include <asm/vtimer.h>
#include <asm/vtime.h>
#include <asm/cpu_mf.h>